Method for casting separate annular castings



Feb. 25, 1969 D. w. WONUS METHOD OF CASTING SEPARATE ANNULAR CASTINGS Sheet Filed Oct. 23, 1965 'INVENTOR. DCl 1Q W. Worm;

Luz- 22.; 1?.

AGENT Feb. 25, 1969 0. w. WONUS 3,429,364

METHOD OF CASTING SEPARATE ANNULAR CASTINGS Filed Oct. 23, 1965 Sheet 2 of 2 AGENT United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE A method for simultaneously casting separate annular articles in a mold having one cavity in the cope and another in the drag. Positioning the drag core within the drag cavity and then positioning the cope core on the drag core by locating means and then accurately placing the cope over the cope core and in contact with the drag by utilizing locating and positioning means on the cope core and drag.

This invention relates to casting apparatus and method and has for an object the provision of improvements in this art. The invention has been developed in connection with the production of cast metal brake drums for auto mobiles and will be described for this use although applicable to other uses.

One of the particular objects of the invention is to increase production of cast articles by making two articles in the same general equipment and at about the same speed as has heretofore been required to make a single article. Production is practically doubled with little or no increase in the cost of production except for the additional cast material required.

Another object is to produce plural articles (lower and upper) which are interconnected only at the gate and which can readily be separated by breaking them apart, thus requiring no machine cut for separation.

Another object is to provide dual, duplex, or twin castings (either alike or unalike) in simple, substantial and easily manipulated casting mold apparatus.

Another object is to provide very accurately positioned and maintained casting-defining elements in a mold.

Another object is to provide casting apparatus which accurately positions a metal insert for incorporation in the casting and which maintains the insert for each of two companion superposed articles accurately in position during casting.

Another object is to provide casting apparatus for forming dual or twin castings which produces accurate castings in each of two cooperating mold parts even if the parts are not accurately aligned with each other as formed by patterns.

The above and other objects of the invention, as well as various features of novelty and advantages, will be apparent from the following description of certain exemplary embodiments, reference being made to the accompanying drawings, wherein:

FIG. 1 is a vertical axial section of apparatus for making a composite brake drum, comprising a preformed head and a cast drum proper, the view being taken on the line 1-1 of FIG. 2;

FIG. 2 is a horizontal plan and section taken about on the line 22 of FIG. 1;

FIG. 3 is a vertical axial section of apparatus for making an all-cast brake drum, the View being taken on the line 33 of FIG. 4;

FIG. 4 is a horizontal section taken on the line 44 of FIG. 3.

In the drawings, referring first to FIGS. 1 and 2, the

3,429,364 Patented Feb. 25, 1969 numeral 10 denotes the drag and the numeral 11 the cope of conventional casting apparatus having separable frames which are locked together for pouring. It is not necessary to show the frames and interlocking means, these being entirely conventional. It is common to make a plurality of parts in one mold assembly, and in the brake manufacturing art it is common to make four drums in one mold unit, one gate serving two laterally adjacent mold cavities. All of the shapes for each the drag and cope are formed by a single pattern unit so that all have a fixed relationship to each other and the relative position of one shape will be the same as for all others; hence only one unit need be considered.

Herein only the rammed greensand or other shapedefining molding material 12 for the drag 10 and the rammed greensand or the equivalent molding material 13 for the cope 11 is shown, the line of parting P being along the upwardly extending portion 14 and the horizontal portion 15 of the gate. The downwardly extending portion 16 and the sprue 17 are in the rammed greensand of the cope. The terminal horizontal portion 18 of the gate branches into lower and upper vertical portions 19 and 20 respectively, and these terminate in horizontal end portions 21, 22 respectively, which lead to lower and upper main casting cavities 23 and 24 respectively. An air chamber 25 is provided above the horizontal portion 18 to reduce flow surges of metal.

Preformed steel drum heads and 31 are arranged in the drag and cope respectively, center openings 32 thereof fitting around central projections 33, 34 formed of rammed greensand in the drag and cope respectively.

The heads 30 and 31 each have an annular rib 35 and an outer annular radial flange 36. The flange 36 fits against an annular radial surface 37 formed in the greensand of the drag or cope. An annular inclined portion 38 of the head is positioned against an annular inclined ribbed portion 39 formed in the greensand of the drag or cope.

In each mold space or cavity, 23 or 24, there is disposed an annular core, 40 lower and 41 upper, having mating medial annular radial portions 42, 43 respectively, and annular axial portions 44, 45 respectively. The cores 40, 41 have a central cavity to save material and outer edges with outer inclined surfaces 47, 48 respectively, which fit against annular inclined surfaces 49, 50 respectively, formed in annular recesses formed in the greensand of the drag and cope. Interfitting elements, including an annular inclined surface 53 on one core member, as 40, and a mating annular inclined surface 54 on the other core member, as 41, serve to hold the core members 40 ad 41 in proper position relative to each other during mold assembly, as will be seen.

The axial portions 44, 45 of the core members 40, 41 are provided each with a tapered surface 55 which cooperates with the outer sides of the rib 35 of the head member, 30* or 31, to position the parts relative to each other. The core members 40, 41 have an annular radial surface 56 at the outer end of the axial portion opposite the radial face 37 of the greensand to hold the radial flange 36 of the head.

The core members 40, 41 are made of very hard strong material, such for example as CO -hardened sodium silicate.

The method of assembly is to place the stamped metal head 30 in the drag, the inclined portion 38 of the head fitting against the inclined ribs 39 of the greensand and the opening 32 of the head fitting around the projection 33 of the greensand to position the head. The head seats on the radial portion at, on the inclined portion 39, and around the projection 33 of the greensand. Next, the core 40 is placed in the drag. The core member 40 seats on the inclined portions 47, 49, on the radial portions 36, 56, and with the inclined portions 55 seated on the inclined outer surface of the rib 35-.

Next, the upper core member 41 is placed on the core member 40, the interfitting portions 53, 54 holding the upper core member in position on the lower core member 40.

Then the head 31 is placed on the upper core member 41, the inclined portion 55 acting against the outer side of the rib 35 accurately locating it on the core member. Finally, the rammed cope 11 is carefully lowered upon the core member 41 and head 31. The inclined portion 48 of the core member is engaged by the inclined surface i) of the pattern-shaped greensand in the cope to accurately position the cope and upper core member 41 relative to each other. The inclined surface 39 of the cope acts against the inclined portion of the head to hold the head in proper position, its mounting on the upper core member 41 providing that it will be approximately in correct position initially.

It is thus seen that the parts for the upper casting are always positioned to make a perfect casting even if the mold frames are not positioned to place the mold cavity of the cope directly over the mold cavity of the drag.

The molten metal fills the cavities 23 and 24 and unites with the outer projecting edges of the heads 30* and 31 without leaking into the interior spaces. Often the outer edge of the head is roughened or otherwise shaped to form a good bond with the molten metal but that is not a part of the present invention.

After solidifying, the two cast parts are connected only at the horizontal portion 18 of the gate and may be broken apart or broken off at the restricted end portions of the channels 21, 22 without requiring machine cuts and without injury to the cast parts.

The form shown in FIGS. 3 and 4 is similar to the first form of FIGS. 1 and 2 in most respects. The differences are that an all-cast drum is made instead of a drum with a preformed head secured in the drum casting and that the upper core member is positioned by the molding material in the drag instead of by interfitting parts between the upper and lower core members, as in the first form. The latter arrangement, of course, would be applicable to the first form. The arrangement provides that the lower or drag molding material will accurately position the lower core member (and head, if used) and will, at least, closely position the upper core member by actual engagement or engagement with the lower core member which it has positioned, and that the upper core member and the cope cavity are accurately located relative to each I other :by such shifting movement of one or the other as may be required when the cope is placed on the upper core member. The upper head plate, when used, is also accurately positioned on the upper core member and rela tive to the cope cavity. In the illustrated forms the upper core member is held firmly by the lower assembly in a fixed position and the cope is caused to shift by the upper core member so much as may be necessary. But it will be obvious that the cope may shift the upper core member relative to the lower core member (if permitted) so that the upper core member is in accurate final registry in the cope cavity if the upper core member is initially held in a generally correct position by the lower assembly so as to take a position to be guided into the cope cavity.

In FIGS. 3 and 4 the parts which correspond to those of the first form of FIGS. 1 and 2 are designated by the same reference characters but with a prime added.

Thus there is a drag and a cope 11', the drag having molding material 12 and the cope having molding material 13' therein.

The gate includes an upwardly extending portion 14, a horizontal portion 15', a common vertical portion 16', a sprue 17, a terminal horizontal portion 18', a lower vertical branch portion 19', an upper vertical portion or branch 20', a lower end portion 22', and an air chamber 25 above the horizontal portion 18. There is a lower casting cavity 23' and an upper casting cavity 24'.

There is a central projection 33 on the molding material in the drag 10' to support and aid in positioning a lower core member 40 and also to form a barrier to the flow of metal so as to form a center opening in the head of the casting. There is a like projection 34' on the molding material in the cope 11' to cooperate with an upper core member 41'.

The lower core member 40 has an annular radial portion 42' and an annular axial portion 44' with a central cavity 46. It also has a closed end or head 51 to shape that part of the inside of the metal cavity :23. The upper core member 41 has an annular radial portion 43' and an annular axial portion 45' with a central cavity 46'. It also has a closed end or head 52.

The lower core member 40 has an annular inclined surface 47' on the outer periphery of its radial portion 42 to fit against an annular inclined surface 49' formed in the molding material 12 in the drag 10'. The upper core member 41' has an annular inclined surface 48 on the outer periphery of its radial portion 43' to fit against an annular inclined surface 50' formed in the molding material 13 in the cope 11.

The locational elements 53, 54 of the first form could have counterparts in this form but they are omitted and their function is replaced by providing a lower annular inclined surface 57 on the upper core member 41 which engages the upper portion of the annular inclined surface 49' on the molding material 13 in the drag 10'. In effect, the parting line of the cores has been displaced so as to be below the parting line P between the molding material in the drag and cope. So, instead of having molding material of the lower assembly position the upper core member and assembly through the lower core member, as in the first form, the upper core member in the second form is directly positioned by the molding material in the lower mold assembly.

The steps of assembling the parts of the second form will be obvious and need not be described. It will be clear that the upper core member, being held in proper position, will cause the cope to be shifted by the inclined surfaces 48, 50' to bring it into correct position relative to the upper core member.

In neither form is the position of the molding cavity in the cope necessarily aligned with the cavity in the drag. It will also be seen that parts of different size and shape can be formed, respectively, in the drag and cope without reference to the size and shape of the article formed in the other. It is even possible to form a full-cast article in one assembly and to form an article on a preformed head in the other assembly.

It is thus seen that the invention provides apparatus and method for producing duplex castings in a drag and cope where only a single casting was previously produced; and that perfect castings are produced in each the drag and cope even though they may not be in perfect registry or alignment.

While certain embodiments of the invention have been described for purposes of illustration, it is to be understood that there may be various embodiments and modifications within the general scope of the invention.

I claim:

1. The method of casting separate annular articles in molding material in opposed drag and cope cavities, which comprises, placing a drag core member in the drag cavity with interfitting engaged tapered surfaces adjacent the parting line accurately defining the position of the drag core member in the drag cavity, placing a cope core member on the drag core member with interfitting surfaces defining its position at least within interengaging limits with tapered positioning surfaces on the cope, and placing a cope on the cope core member with interfitting engaged tapered surfaces adjacent the parting line accurately dcfining the position of the cope core member and the cavity in said cope.

2. The method as set forth in claim 1, further characterized by the fact that said cope core member is posi tioned by interfitting surfaces on the cope core member and the drag core member.

3. The method as set forth in claim 1, further characterized by the fact that said cope core member is accurately positioned by interfitting tapered surfaces between said cope core member and one of said drag core member and said drag molding material.

4. The method as set forth in claim 3, further characterized by the fact that said cope core member is accurately positioned by interfitting tapered surfaces between said cope core member and the molding material of the drag near the parting line.

5. The method of casting annular articles in molding material in opposed drag and cope cavities, which comprises, placing a first preformed head insert in the bottom of the drag cavity against positioning element stherein, placing a first core member on said first head insert which positions on elements on said first head insert and on the molding material in said drag, the first core member having an annular radial portion and an annular axial portion spaced inwardly of the outer periphery of the radial portion to leave metal space around the annular axial portion and below the annular radial portion, and the core member having an upper interface surface adjacent the parting line between the drag and cope, placing a second core member in reverse position on said first core 0 comprises, laterally positioning the core members by interfitting tapered surfaces on the outer edges of the annular radial portions of said core members and mating annular tapered surfaces formed in the molding material of the drag and cope.

References Cited UNITED STATES PATENTS 818,413 4/1906 Caldwell 164397 1,952,500 3/1934 Huetteman 249-142 X 2,218,810 10/1940 Campbell et al. 164-351 X 2,560,258 7/1951 Snyder et al 164370 3,302,919 2/1967 Beetle et al. 16 1-340X 3,374,827 3/1968 Schebler 164-397 X J. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner.

US. Cl. X.R. 

